Alternative Network Service for Video Conferencing Applications

1. A method of establishing a communication connection between a first terminal and a second terminal, wherein the first and second terminals are configured for communicating over a primary network, the method comprising: receiving at a dial-out unit a first call setup message from the first terminal over a first signaling channel, the first call setup message including an identifier of the second terminal; determining whether to establish a communication session between the first and second terminals over an alternative network based on the identifier of the second terminal; outputting from the dial-out unit to a dial-in unit, over a data channel, the identifier of the second terminal; and outputting from the dial-in unit to the alternative network, over a second signaling channel, a second call setup message and the identifier of the second terminal, wherein the alternative network is an asynchronous transfer made (ATM) network, the first and second signaling channels are ISDN D-channels, and the data channel is an ISDN B-channel.

2. The method of claim 1 , wherein the primary network is an integrated services digital network (ISDN).

3. The method of claim 1 , further comprising: receiving from the alternative network, over the second D-channel, a D-channel connection message indicating that a connection with the second terminal is established; sending a B-channel connection message over the B-channel to the dial-out unit in response to receiving the D-channel connection message; and sending a D-channel connection message from the dial-out unit to the first terminal in response to the B-channel message for indicating to the first terminal that a connection is established with the second terminal.

4. The method of claim 1 , wherein the first and second terminals conform to ITU-T Recommendation H.320.

5. The method of claim 1 , further comprising: outputting from the dial-out unit, over the data channel, an identifier of the dial-out unit; and determining, based on the identifier, if the dial-out unit is authorized to use the alternative network, wherein the dial-out unit outputs the second call setup message only if the dial-out unit is determined to be authorized to use the alternative network.

6. A method of establishing a communication connection over an alternative network between first and second terminals configured for communicating over a primary network, comprising: receiving a first call setup message on a first signaling channel, the first call setup message containing an identifier for communicating with the second terminal; determining if the identifier in the first call setup message corresponds to predetermined location information; initiating the sending of a second call setup message to the alternative network in response to determining that the identifier in the call setup message corresponds to the predetermined location information; bridging the first and second signaling channels with a data channel; receiving over the data channel call setup information from the alternative network concerning the second terminal; and outputting said call setup information over the first signaling channel to the first terminal, wherein the primary network is an integrated services digital network (ISDN), the first and second signaling channels are ISDN D-channels, and the data channel is an ISDN B-channel.

7. The method of claim 6 , wherein the alternative network is an asynchronous transfer mode (ATM) network.

8. The method of claim 6 , wherein the identifier is an ISDN destination address of the second terminal.

9. The method of claim 6 , wherein the first and second terminals are video codec units conforming to ITU-T Recommendation H.320.

10. The method of claim 6 , wherein the identifier in the call setup message is an address of the second terminal.

11. The method of claim 10 , wherein the address of the second terminal includes a country code and said address is determined to correspond to the predetermined location information if the country code corresponds to a country serviced by the alternative network.

12. An apparatus for establishing a call between a first terminal and a second terminal, wherein at least the first terminal is configured for communicating over a primary network, by using an alternative network, the apparatus comprising: a terminal port suitable for connecting to the first terminal; a network port suitable for connecting to a local network; a network protocol unit connected to the terminal and network ports; a processor connected to the network protocol unit; and a memory unit connected to the processor, wherein the memory unit includes: an alternative network address storage area configured for storing at least one address for communicating with the alternative network, a service location storage area configured for storing at least one indicator of location serviced by the alternative network, and an instruction area having stored therein instructions for controlling the processor to determine, based on an identifier of the second terminal contained in a call setup message received from the first terminal by way of the terminal port, if the alternative network services an area in which the second terminal is located; output from the network port a call setup message addressed to the alternative network in response to determining that the alternative network services an area in which the second terminal is located, and output from the network port an address of the second terminal, wherein the primary network is an integrated service digital network (ISDN), the call setup message received by the terminal port is received over an ISDN D-channel, and the call setup message and address of the second terminal output from the network port are output over an ISDN B-channel.

13. The apparatus of claim 12 , wherein the instruction area has further instructions stored therein for controlling the processor to output a connect message to the terminal port for indicating to the first terminal establishment of a connection with the second terminal.

14. The apparatus of claim 12 , wherein the secondary network is an asynchronous transfer mode (ATM) network.

15. The apparatus of claim 12 , wherein the instruction area has further instructions stored therein for controlling the processor to receive changes to said at least one indicator of a location serviced by the alternative network.

16. The apparatus of claim 12 , wherein the apparatus is an ISDN dialer.

17. The apparatus of claim 12 , wherein the instruction area includes instructions for controlling the processor to output an indicator of the identify of the apparatus.

18. A computer-readable medium of instructions, suitable for use in a device for establishing a call between a first terminal and a second terminal, wherein at least the first terminal is configured for communicating over a primary network, by using an alternative network, the computer-readable medium of instructions comprising: program instructions for determining, based on an identifier of the second terminal contained in a call setup message received from the first terminal by way of the terminal port, if the alternative network services an area in which the second terminal is located; program instructions of outputting from the network port a call setup message addressed to the alternative network in response to determining that the alternative network services an area in which the second terminal is located; and program instructions for outputting from the network port an address of the second terminal, wherein the call setup message is output on an ISDN D-channel, and the address of the second terminal is output on an ISDN B-channel.

19. The computer-readable medium of instructions of claim 18 , wherein the primary network is an integrated services digital network (ISDN) and the alternative network is an asynchronous transfer mode (ATM) network.

20. The computer-readable medium of instructions of claim 18 , wherein the first and second terminals conform to ITU-T Recommendation H.320.

21. The computer-readable medium of instructions of claim 18 , wherein the identifier in the call setup message is an address of the second terminal.

22. The computer-readable medium of instructions of claim 21 , wherein the address of the second terminal includes a country code and said alternative network is determined to service an area in which the second terminal is located address if the country code corresponds to a country serviced by the alternative network.

23. A method of establishing a communication connection over an alternative network between first and second terminals configured for communicating over a primary network, comprising: receiving a call setup message over a signaling channel for establishing a connection with the second terminal over the alternative network; receiving an address of the second terminal over a data channel; sending a message with the address of the second terminal to the alternative network for establishing a connection with the second terminal, in response to receipt of the call setup message; and sending an indication over the data channel that the alternative network has established a connection with the second terminal, wherein the primary network is an integrated services digital network (ISDN), the first and second signaling channels are ISDN D-channels, and the data channel is an ISDN B-channel.

24. The method of claim 23 , wherein the alternative network is an asynchonous transfer mode (ATM) network.

25. The method of claim 23 , wherein the address is an ISDN destination address of the second terminal.

26. The method of claim 23 , wherein the first and second terminals conform to ITU-T Recommendation H.320.

27. The method of claim 23 , wherein the identifier in the call setup message is an address of the second terminal.

28. The method of claim 23 , further comprising: receiving an indicator of the identify of an originator of the call setup message; and based on the indicator determining if said originator is authorized to use the alternative network.

29. An apparatus for establishing a call between a first terminal and a second terminal, wherein at least the first terminal is configured for communicating over a primary network, by using an alternative network, the apparatus comprising: a local network port suitable for connecting to a local network; an alternate network port suitable for connecting to a switch in the alternate network; a network protocol unit connected to the local and alternate network ports; a processor connected to the network protocol unit; a memory unit connected to the processor, wherein the memory unit includes instructions for controlling the processor to extract the second terminal address from a data channel message received via the local network port; outputting from the alternate network port a message containing the address of the second terminal for controlling the alternate network switch to make a connection with the second terminal; and outputting from the local network port a message on the data channel indicating establishment of a connection with the second terminal, wherein the local network is an integrated services digital network (ISDN) and the data channel is an ISDN B-channel.

30. The apparatus of claim 29 , wherein the primary network is an integrated services digital network (ISDN).

31. The apparatus of claim 30 , wherein the alternative network is an asynchronous transfer mode (ATM) network.

32. The apparatus of claim 30 , wherein the address of the second terminal is an ISDN destination address of the second terminal.

33. The apparatus of claim 29 , wherein the first and second terminals conform to ITU-T Recommendation H.320.

34. The apparatus of claim 29 , wherein the memory unit includes instructions for controlling the processor to determine if an originator of a message containing said second terminal address is authorized to use the alternative network.

35. An apparatus for establishing a call between a first terminal and a second terminal, wherein at least the first terminal is configured for communicating over a primary network, by using an alternative network, the apparatus comprising: a local network port suitable for connecting to a local network; an alternate network port suitable for connecting to a switch in the alternate network; a network protocol unit connected to the local and alternate network ports; a processor connected to the network protocol unit; and a memory unit connected to the processor, wherein the memory unit includes instructions for controlling the processor to extract the second terminal address from a data channel message received via the local network port; outputting from the alternate network port a message containing the address of the second terminal for controlling the alternate network switch to make a connection with the second terminal; outputting from the local network port a message on the data channel indicating establishment of a connection with the second terminal, wherein the alternate network port connects to an integrated services digital network (ISDN) and message output from the alternate network port is output over an ISDN D-channel.

36. The apparatus of claim 35 , wherein the primary network is an integrated services digital network (ISDN).

37. The apparatus of claim 36 , wherein the alternative network is an asynchronous transfer mode (ATM) network.

38. The apparatus of claim 36 , wherein the address of the second terminal is an ISDN destination address of the second terminal.

39. The apparatus of claim 35 , wherein the first and second terminals conform to ITU-T Recommendation H.320.

40. The apparatus of claim 35 , wherein the memory unit includes instructions for controlling the processor to determine if an originator of a message containing the second terminal address is authorized to use the alternative network.

41. A computer-readable medium of instructions, suitable for use in a device for establishing a call between a first terminal and a second terminal by using an alternative network, wherein at least the first terminal is configured for communicating over a primary network, the computer-readable medium of instructions comprising: program instructions for extracting an address of the second terminal from a received data channel message; program instructions for outputting to a switch of the alternative network a message containing the address of the second terminal for controlling the alternate network switch to make a connection with the second terminal; and program instructions for outputting a data channel message indicating establishment of a connection with the second terminal, wherein the primary network is an integrated services digital network (ISDN), the alternative network is an asynchronous transfer mode (ATM) network, and the received and output data channel messages are a message received and output on an ISDN B-channel, respectively.

42. The computer-readable medium of instructions of claim 41 , wherein the first and second terminals conform to ITU-T Recommendation H.320.